Low FODMAP green bean casserole in 45 minutes, made completely from scratch, with no canned cream of mushroom soup in sight. Gluten free, dairy free, and simple enough to pull off on a busy holiday weekend or a regular Tuesday night. One casserole dish, one pan for the topping, and everyone at the table eats the same thing. No negotiations required.
Green bean casserole has been a non-negotiable in our house for years. When the low FODMAP diet entered the picture, it was one of the first recipes I refused to just quietly drop from the menu. The original calls for canned cream of mushroom soup, French fried onions, and regular milk - none of which are easy on a sensitive gut. So I rebuilt it from scratch using ingredients that actually work. My family had zero complaints.
The from-scratch mushroom sauce is where all the magic happens. Dairy free butter, gluten free flour, low FODMAP chicken stock, almond milk, and coconut cream come together into something thick, savory, and genuinely satisfying. And the topping is shoestring potatoes tossed with nutritional yeast and baked until crispy - same crunch as the classic, none of the triggers.
If cozy from-scratch side dishes are your thing, my Low FODMAP Stuffing belongs on the same holiday table as this one. It is built the same way - real ingredients, no shortcuts that wreck your gut, and nobody at the table feels like they are eating a "special" version of anything.
Jump to:
- Why You'll Love This Recipe
- What You'll Need
- Step-by-Step Instructions
- Tips and Tricks
- Green Bean Casserole Toppings Without Fried Onions
- Gluten Free and Dairy Free Variations
- Storing and Reheating
- Low FODMAP Notes
- FAQs
- What To Serve With Low FODMAP Green Bean Casserole
- More Loveable Side Dish Recipes
- Love This Recipe?
- Recipe
Why You'll Love This Recipe
- Made completely from scratch - no canned cream of mushroom soup and no canned soup of any kind
- Gluten free, dairy free, and low FODMAP all in one dish
- Crispy shoestring potato topping with nutritional yeast instead of French fried onions
- Prep it the day before to save oven space during the holidays - a total lifesaver on Thanksgiving
- The whole table eats the same dish with zero modifications. That counts as a win.
What You'll Need
Only the ingredients worth talking about are listed here. See the recipe card for exact measurements and complete instructions.
- Dairy Free Butter - The base of the roux. Any dairy free butter substitute works well here.
- Gluten Free Flour - Use a 1-to-1 gluten free flour blend with xanthan gum. Bob's Red Mill 1-to-1 in the blue bag is what this recipe was tested with and it nails the texture every time.
- Low FODMAP Chicken Stock - Use a certified low FODMAP stock or one you know you can tolerate. This is where a lot of the savory flavor in the sauce comes from, so use a good one.
- Unsweetened Almond Milk - Adds body and creaminess to the sauce without any dairy.
- Full-Fat Unsweetened Coconut Cream - This is what makes the sauce feel genuinely rich. Full-fat matters here. Coconut milk is too thin and the sauce will not come together the same way.
- Canned Mushroom Pieces - Drained and rinsed before using. Canned mushrooms are the low FODMAP move here because canning leaches the fructans into the liquid. Rinse them well and they are good to go.
- Gluten Free Soy Sauce - Adds umami depth to the sauce. Check the label - not all soy sauce is gluten free. Certified gluten free tamari is a reliable option.
- Shoestring Potatoes - The crispy topping that steps in for French fried onions. Baked separately so they stay crunchy and added right before serving. Do not skip this step.
- Nutritional Yeast - Sprinkled over the shoestring potatoes before baking. Adds a savory, slightly cheesy flavor without a single drop of dairy. It sounds odd if you have never used it, but it works like a charm.
See the recipe card for the exact measurements and complete instructions.
Selected ingredients are based on guidance on current serving sizes measured by the Monash University Food App and FODMAP Friendly App at the time of publishing. As always, follow your gut and modify as needed.
Step-by-Step Instructions
Step 1: Preheat and Melt
Preheat the oven to 350 degrees F. In a large skillet, melt the dairy free butter over low to medium heat. Once melted, sprinkle the gluten free flour over the top and whisk them together. A flat whisk makes this step much easier.
Step 2: Add the Flour
Sprinkle the gluten-free flour over the melted butter in the skillet.
Step 3: Whisk the Roux
Using a whisk (a flat whisk is my favorite) whisk the butter and flour together until smooth.
Step 4: Add the Broth
Pour in half of the chicken broth and whisk. It will look clumpy at first. Keep whisking, then add the remaining broth and whisk again until it starts to look like a sauce.
Step 5: Stir in Almond Milk
Whisk in the unsweetened almond milk until the sauce is smooth.
Step 6: Finish the Creamy Base
Add the coconut cream and whisk again until the sauce is silky and lump-free.
Step 7: Season and Add Mushrooms
Chop the mushrooms if you prefer smaller pieces. Add the mushrooms, gluten-free soy sauce or coconut aminos, and black pepper. Whisk to combine, then turn off the heat.
Step 8: Combine With Green Beans
Grease a casserole dish. Add the partially thawed green beans and pour the hot sauce evenly over the top.
Step 9: Crisp the Topping
Line a baking sheet with parchment for easy cleanup. Spread the shoestring potato chips in a single layer and sprinkle evenly with nutritional yeast.
Place the casserole and the topping in the 350 degrees F oven. Bake the casserole for about 30 minutes or until bubbly, and bake the shoestring potatoes for about 20 minutes or until crispy and golden.
Step 10: Top and Serve
When the casserole is done, sprinkle the crispy shoestring potatoes over the top and serve right away.
Tips and Tricks
Bake the topping separately. This is the most important tip in this entire post. If you add the shoestring potatoes on top of the casserole from the start, they turn soft and lose all their crunch. Bake them on a separate sheet pan and add them right before serving. Every time.
Prep it the day before. Make the green bean and sauce portion completely the day before and refrigerate it covered. Store the shoestring potato mixture separately in a bag. On Thanksgiving or whatever day you are serving it, reheat the casserole and bake the topping fresh. This is a huge help when oven space is limited.
The sauce will look thin when you pour it. That is normal. It thickens as it bakes. Trust it.
Use a flat whisk for the roux. It gets into the corners of the pan and keeps lumps from forming. Worth having in the kitchen if you do not already.
Check your soy sauce label. Not all soy sauce is gluten free. Look for a certified gluten free tamari or a product that is clearly labeled. I do the same check for my gluten free casserole recipes across the board - hidden gluten shows up in the most unexpected places.
Green Bean Casserole Toppings Without Fried Onions
The classic topping for green bean casserole is French fried onions, which are not low FODMAP and usually not gluten free either. Shoestring potatoes with nutritional yeast is the move here, and it is genuinely good. But if you want to mix it up, here are more options that work:
- Gluten free breadcrumbs - toss with a little dairy free butter and toast on a sheet pan until golden brown
- Crushed rice crackers - a simple swap with great texture and a mild flavor
- Chopped toasted almonds or pecans - adds crunch with a slightly nutty finish
- Parmesan cheese - low in lactose and adds a great savory bite if dairy is not a concern for you
- Crispy canned French fried onions - if they fit your dietary needs and you can tolerate them, they work great here
Whatever you use, bake the topping separately and add it right at serving time. Zero soggy topping drama.
Gluten Free and Dairy Free Variations
Gluten Free Green Bean Casserole (with dairy): Not dairy free? Use regular butter and regular milk in place of the dairy free swaps. Everything else stays exactly the same.
Green Bean Casserole Without Mushrooms: Not a fan of mushrooms? Skip the canned mushroom pieces entirely. The from-scratch sauce still works and still tastes great without them.
Gluten Free Dairy Free Green Bean Casserole: This recipe is already both - just follow it as written. No swaps needed.
Vegetarian Low FODMAP Green Bean Casserole: Swap the low FODMAP chicken stock for a low FODMAP vegetable broth. Same steps, same result.
Extra Creamy Version: Double the coconut cream for an even richer sauce. This is a great option if you are serving it as a main side dish rather than one of many on a holiday spread.
I haven't tested these variations in my kitchen. If you replace or add any ingredients, please let us know how it turned out in the comments below!
Storing and Reheating
Store: Keep leftovers in an airtight container in the refrigerator for up to four days. Store any remaining shoestring potato topping in a separate container so it does not go soggy.
Reheat: Warm in a 350 degree F oven for 15-20 minutes or microwave individual servings for 1-2 minutes. Add a fresh sprinkle of shoestring potato topping right before serving again if you have any left.
Freeze: This casserole does not freeze well. The dairy free sauce tends to separate once thawed and the green beans lose their texture. Make it fresh or prep it up to one day ahead instead.
Low FODMAP Notes
Low FODMAP ingredient information is based on the Monash University Food App and FODMAP Friendly App testing results as of the day posted. As always, modify based on your gut and what works for you on a low FODMAP diet.
- Frozen Green Beans - Green beans are low FODMAP and a great vegetable option for a modified diet. Canned green beans (drained) also work.
- Dairy Free Butter - Low in FODMAPs at typical cooking amounts.
- Gluten Free Flour - Safe for a gluten free diet. Check your specific blend for any added high FODMAP ingredients.
- Low FODMAP Chicken Stock - Use a certified low FODMAP option like Gourmend Foods or one you know works for you. Safe at 1 cup or 237 grams per meal.
- Unsweetened Almond Milk - Safe at 1 cup or 250 grams per meal.
- Full-Fat Coconut Cream - Safe at ¼ cup per meal.
- Canned Mushroom Pieces, Drained and Rinsed - Canning leaches the fructans out of mushrooms into the liquid. Drain and rinse well before using and they become a low FODMAP option. This is the same approach I use for the black beans in my Low FODMAP Taco Soup - same great result.
- Gluten Free Soy Sauce - Safe at 2 tablespoons or 42 grams per meal.
- Shoestring Potatoes - Potatoes are low FODMAP. Check the label on your specific brand for any added ingredients.
- Nutritional Yeast - Safe at 2 tablespoons per meal.
For additional information on a low FODMAP diet, please visit Monash University or FODMAP Friendly. Both have websites and apps for additional guidance and testing results.
FAQs
Traditional green bean casserole is not low FODMAP. It is typically made with canned cream of mushroom soup, French fried onions, and regular milk - all of which contain high FODMAP ingredients. This from-scratch version replaces all of those with low FODMAP alternatives so the whole dish works for a low FODMAP diet.
A from-scratch sauce made with dairy free butter, gluten free flour, low FODMAP chicken stock, unsweetened almond milk, and coconut cream is the best swap. It gives you the same creamy, savory result without any of the canned soup ingredients. This is exactly what this recipe does, and it honestly tastes better than the original.
Traditional green bean casserole is not gluten free because canned cream of mushroom soup contains wheat and French fried onions are typically coated in wheat flour. This gluten free green bean casserole uses gluten free flour for the sauce and skips the fried onions entirely. Just make sure your soy sauce is certified gluten free.
Traditional green bean casserole is not dairy free. This version uses dairy free butter, almond milk, and coconut cream in place of all dairy ingredients. The result is a creamy, rich dairy free green bean casserole that tastes just like the classic.
Yes, and it is highly recommended especially during the holidays. Make the green bean and sauce portion completely the day before and refrigerate it covered. Keep the shoestring potato topping stored separately. On serving day, reheat the casserole and bake the topping fresh. Add the topping right before it hits the table.
Shoestring potatoes with nutritional yeast baked until crispy is the move here. Other great options include gluten free breadcrumbs toasted with dairy free butter, crushed rice crackers, chopped toasted almonds, or Parmesan cheese if dairy is not a concern. The key is always baking the topping separately and adding it right before serving.
Yes. Trim the stem ends, wash them well, and use them just like the frozen version. You may need to add a few extra minutes of bake time.
Yes. Drain them well before adding to the casserole dish. Canned beans are already soft, so the bake time stays the same.
Not really. Full-fat coconut cream blends into the sauce and picks up all the savory flavors from the stock and soy sauce. It adds richness without tasting tropical. Most people cannot identify it at all.
If you bake them on top of the casserole from the start, they absorb moisture and go soft. Baking them on a separate sheet pan keeps them crispy so they can actually do their job as the topping. Same rule applies to any casserole with a crunchy topping.
Yes. Leave the canned mushrooms out entirely. The sauce still works and still tastes great.
What To Serve With Low FODMAP Green Bean Casserole
This casserole belongs on a holiday table, but it is also solid enough for a regular weeknight dinner alongside a simple protein. Pair it with Low FODMAP Pork Tenderloin for a dinner that feels fancy without much effort. For a full Thanksgiving spread, add almond milk mashed potatoes and Low FODMAP Cranberry Sauce and you have a complete low FODMAP holiday side dish lineup that works for everyone at the table. My Low FODMAP Gravy rounds it out perfectly if you want to go all in.
More Loveable Side Dish Recipes
- Low FODMAP Stuffing (Gluten Free and Dairy Free)
- Low FODMAP Green Beans with Lemon Sauce
- Roasted Delicata Squash
- Low FODMAP Oven Roasted Vegetables
Still looking for the perfect side dish recipe? Discover something new or find an old favorite!
Love This Recipe?
Leave a ⭐⭐⭐⭐⭐ rating + comment. It helps so much, and we love hearing from everyone! Thank You -Venessa
Recipe
Low FODMAP Green Bean Casserole
Ingredients
- 12 ounces frozen green beans, cut or fine (Note 1)
- 3 tablespoons dairy free butter
- 3 tablespoons gluten free flour (Note 2)
- 1 cup low FODMAP chicken stock
- 1 cup unsweetened almond milk
- ½ cup full-fat, unsweetened coconut cream
- 4 ounces mushroom pieces canned and drained
- 1 teaspoon freshly cracked black pepper
- 1 tablespoon soy sauce gluten free, (Note 3)
- 2 cups shoestring potatoes
- 2 tablespoons nutritional yeast
Instructions
- Preheat oven to 350 degrees F.
- In a large skillet, melt the dairy free butter on low to medium heat to make the homemade mushroom sauce.
- Once melted, sprinkle the gluten free flour over the melted butter.
- Whisk together the melted butter and the flour. A flat whisk works well.
- Once the butter and flour are completely combined, add half of the chicken broth. Whisk the broth into the flour mixture. The broth will hydrate the flour and form clumps. It is ok. Keep whisking. Add the other half of the broth and whisk again. The mixture will begin to look like a sauce.
- Next, add the unsweetened almond milk to the skillet. Whisk into the sauce.
- Once the almond milk is mixed in, add the unsweetened coconut cream. And whisk again.
- Add the chopped mushrooms, soy sauce, and black pepper to the creamy sauce. Whisk it until all combined. Turn the heat off.
- If using frozen green beans, heat in the microwave for three minutes to thaw a bit. If using fresh green beans, snip off the stem end and wash thoroughly.
- In a greased casserole dish, add the partially thawed green beans and pour the sauce over them.
- On a baking sheet, lay down a sheet of parchment for easy cleanup. Next, spread the shoestring potatoes in a single layer. Sprinkle the nutritional yeast evenly over the shoestring potatoes.
- Place the green beans in a baking dish on an oven rack and the shoestring potatoes in a preheated 350 degree F oven. Bake the green beans for 30-35 minutes or until bubbly. Bake the shoestring potatoes for 20-25 minutes or until crispy brown.
- Once the green beans are done baking, sprinkle the shoestring potatoes over the top and serve immediately.
- If you are not serving the green bean casserole immediately after baking, wait until just before serving to bake the shoestring nutritional yeast mixture and add just before serving. The green bean casserole can be prepped the day before and reheated to save on oven space. Keep the shoestring potato mixture and the green bean casserole separate until serving. The shoestring potatoes will get soggy.
- Keep any leftovers in an airtight container in the refrigerator for up to four days.
Venessa Mandelkow says
Made this for a side dish and there were no leftovers! Added additional shoestring potatoes because I love them!